Knee-joint for artificial limbs.



- J. E. JBPSON. KNEE JOINT FOR ABTII'IGIALLIMBS. APPLwATIoN r'xLnn Nov. 2a, 1am;

927,973.; ABatend Ju`1yr13, 1909.

l l A I,12mm Jafar: l Y A meyw No.' 927,973. w

JOHN H. JEPSON, or MINNEAroLIs,` MINNESOTA.

` KNEE-JOINT FOR ARTIFICIL LIMBS.

Specification of Letters 'Patent'.

i Application led November 23, 1907. Serial No. 403,4S3.

Patented Juiyi, loos.

To all whom it may concern: q Be it known' that I, JOHN H. Jnrson, a citizen of the United -States, residing at Minneapolis, in the county of Hennepin 4and 5 State of Minnesota, `have invented certain new and useful Improvements in Knee- Joints for Artificial Limbs and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it. appertains to make and use the same.

My invention relates to artificial legs and has for its object to' provide an improved knee joint or pivotal connection between the metallic st 'aps used to connectt-he lower leg section to the upper leg section.

To the above ends the invention consists of the novel devices and vcombinations of devices hereinafter described and defined in the claim.

The invention is illustrated in the accornpanying drawings whei'ein like characters indicate like parts throughout the several views.

referring to the drawings, Figures 1 and 2 are vie-ws in side elevation, showing a pair of metal straps of the kind above indicated connected by niy improved joint, looking at the outer side thereof. Fig. 3 is a. fragmentary viewv in side elevation, showing thel pivotally connected end portions of the two metal straps, looking at the inner side thereof. Fig. d is a View corresponding to Fig. El, but with some parts broken away and some parts sectioned. Fig. 5 is a trout edge elevation of the parts shownin Figs. El and vt; and Fig. tl is an enlarged section taken on the line ait' a of Fig. l.

The numerals l and 2 indicate, respec- 40 tively, the upper and lower metal straps, one of which and, as shown, the latter of which, is bifnrcated at its pivoted end to form lat e all y spaced cars 3 that embrace and closely engage the sides of the lower end of thc upper strap l. The lower end ofthe upper strap l. which works between the*y ears 3, is bored through to forni a seat that -'closely tits a hub or .so-called bolt Il. This hub 4;, at one end, vis provided with a slight enlargement tliatforms an annular shoulder 5. The

inner end of vthus hul,` l bears against the in-` ner surface of one of the ears 8, and the enlarged outer end thereof closely tits a seat formed in thc other ear. A screw G, the head of which is preferably slightly countersunk into the ear 3 against which the reducedeiid of the hub 4 bears. has screw-threaded en! f gagenient with said hubl and rigidly clamps the same in working position4 in respect to `the two ears 5l, The shoulder of the hub l prevents spreading of thesaid ears.

That

portion of the lower en'd of the strap 'l 4that fgentially cxteinled stop surfaces' T and Tl.

The bifurcated end of the strap 2 between the ears 3 isufornied with a straight stop surface S that extends tangentially to the segmental bearing surface 'T and closely' en` gagesthe said `surface 'T when the straps are movedfpivotally. one with respect to the other. Also` with this construction it follow,`l that whei'i the straps l. and 2 arc moved into approximately straight line with each other. as indicated in Figs. l and ll, the tangential stop surface 7 of the strap l will strike flatwise and throughoutits'length against the bearing surface 8; and lili'ewise when the two straps are moved to their otherextrcnie position, as indicated in l `ig. 2, the tangential stop surface 7" will be thrown flat wise' against the said bearing surface S.

It also follows that at all times,'whether in extreme positions, or in an intcrnufdiate position, the joint has a double. bearing which greatly reduces thc wear between the frie-v tionally engaging partl of thc pivotal joint. For instance, when thc straps aic in intermediate positions, the joint has a licaring between the hub l and its seat. insaid strap l, and between the segmental bearing surface 'i' of said strap l and the tangential bearing surface 8 of the strap rl`his. as is evident. gives a joint that will not only wear a loing time, but which will be free. from all slack or lost motion incident to wear. i l These knee jointsi in artificial leg:` are. sub1 ject to considerable strains and to constant W921i', and the cooperating stop surfaces for lin'iitng the movements of the joint arisubject to a sort of pounding action that tends to distort the saine. This is minimized in the present joint by the tangeutially engaging stop surfaces of the two straps.

Preferably the lower end of the strap 1.

is )roi-ideil in one face `with au annular oil groove. t) which has an upwardlyextended entrance groove l0. through which latter the oil may be introduced into thesaid oil il -hi .lower leg section to vthe upper leg Section of the :11.1.1 tcml leg and that these will be :ip``

plied onepair to ,eachlside'ot'fthe leg. Preferably thestrnps l will'be'jsecureduto the upper leg section. while the straps 2 will be secured; to the lower legl section., For convel'iience, theee Should lie-:ipp'lielto the leg with Vthe hen-de` of theA screws outward. In

'n.ctunl practice the improved joint above described has been found highly etlicient for the l'nn'poses'lnul .in View. y From what has been Saul 1t wlll be underscribed is especiellyedepted -for use in connectionwith artificiel legs designed forl :un-l

putntionsbelowthc knee. 4It is, however, capable of-inore genersil use. l

The bearing surface ofthe 'hub 4:. und. the engaging Sent in the sti-np .1- 'hnve' true cylindrical Surfaces, that is, are'not taperedl or conical. -A tapered 'or conical surface wears uneveuly und the larger diameter 'thereof lwe rs away more rapidly than i113 smaller diemeter, thusxsoon givingP'l'yA- b e-' tween the perts',zwh1le truev .'cylin rica surf- 'A'feceS have an even .,bearing'throughout, and consequentlyreduce the weer to-a1nin1mu1n.

. What I cla-im is:

In a devicefor connectingjthe sections' of an `"artificiallimb, the combination vwithv n metal strep having laterally spaced ears'3: `and a.,tengentialbeering surface 8 between Saidwestrs, of a lnetel strap v1,'jone end of which .isv located between said ears 'and is formed with the 4segunentel .bearing surfaces 7 and tngential stop surfaces 7-'7"engage' able with seicl'beering surface 8, a hub 4 fitting a seat `in seid strap l that is concen# trie to said segmental surface 7, Sii-id hub having eshoulleredA .end 5 seated in one of l the earS 3, ande screw securelycleinping seidl hub to the other ear 3, substnn'tlzillv as described.

, In" testimony whereof I' afiii; my signature in presence 'of two witnesses.

i JOHN H. JEPSON. /Vitnesses: l H. D. KliLGoRE,

F. D.' MERCHANT. 

